Dr. Fast should be your first phone call if you have an allergy or immunology issue. Allergies and infections can be misdiagnosed or ignored, with dire consequences and suffering if not treated early and accurately. I had a mystery pain that doctors could not figure out. Dr. Fast is smart and kind. She listened to my story for 5 min and was able to rapid-fire triage and provide a rare infection as a possible root cause. She proposed a simple test -- taking ibuprofen -- to confirm or rule out the infection. Imagine that -- instead of making me go get an elaborate, inconvenient, and time-consuming blood draw at a blood lab to confirm or rule out the cause, Dr. Fast gave me a free, self-administered test: take ibuprofen during a pain episode, if I don't have pain, it's the infection, if I still have pain, it might be something else. She is a genius with a big brain and a giant heart. For the Yelpers who didn't have the same experience, well, maybe they just don't understand competence and compassion when they experience it? I had to meet a lot of doctors in my mystery pain journey. Honestly, Dr. Fast is the best. She's a great communicator and one of those Harvard University/Yale Medical School/Stanford Medical School experts that could be talking on TV. In spite of the fact Dr. Fast could brag about going to Hahvahd, she keeps her impressive credentials to herself, is down-to-earth, is a great communicator with excellent bedside manner for all age groups and walks-of-life, including kids, seniors, young and middle-aged adults. Please google Dr. Katharine Fast and be blown away that the Internet agrees with me that she's the best allergy and immunology specialist in San Francisco and the Bay Area. You should book an appointment with Dr. Fast if you want an accurate, brilliant, approachable, and nice allergy and immunology expert on your side. read more

I really appreciated my visit with Dr Fast. She listened to me, thought things through, and empathized with my desire to get back to what I consider to be normal, not just a "clinically normal". Plus she was funny - she kept things light hearted and amusing all along! I can tell that she cares about the human, which is relatively rare for specialists. read more

Brilliant doc! Super good listener and thoughtful analysis of complex issues. Dr Fast is honest, caring and has a mind & synthesis of data that are more comprehensive than 99% of doctors. read more

My 5 month old son was dealing with eczema issues and we wanted to test him for allergies to see if there was something causing all of his redness and weeping fluid from the back of the head. We originally went to UCSF who recommended steroid creams which helped to reduce the inflammation and keep it under control but we didn't want to stay on steroids forever. When we visited her, she mentioned that allergy testing wasn't very accurate until he is older and strongly pushed us to keep putting on steroids. What surprised us though was that she asked us about vaccines and started to be quite aggressive about it when we mentioned that we were a bit behind. We have been slowing down the vaccines since we wanted to let his skin calm down first. However, she kept going on about how vaccines saves lives and that we had to get him vaccinated. During the appointment, she saw a hive on our son's forehead and immediately injected something into him... we were surprised that she did that and only after the fact answered our question of what it was... which was something similar to Benadryl. At any rate, her advice was just to keep putting on steroids everyday and as much as possible since that would "protect" the skin and prevent issues in the future. She wanted us to keep increasing the dosage and slathering it on if we saw any redness. She didn't really help with the allergies or give potential suggestions on allergies. When we asked her if we could follow-up with any questions through email, she said that she doesn't email and we have to visit her again in person. It took months to get an appointment with her so we would have waited even longer before getting any "help". My wife and I ended up having to investigate on our own and we found out that our son has allergies to wheat (itchy hives) and oat (redness). When we cut those out, we were able to completely cut out steroids without any issues. He has been fine for 7-8 months now. We couldn't believe that someone who specialized in allergies couldn't even offer any sensible tips or advice for us. read more

Most efficient, compassionate and personable doctor I have had. I have severe pollen and grass allergies, had bounced around to other doctors before I found her. The best read more

BEWARE - Dr Fast charges $750 per hour and makes you pay before any services or care are rendered. I came to her with the desire to start allergy shots only to find out after wasting $750 that she doesn't even offer them, instead she wants you to buy her "special drops" at additional cost. It would have been nice to tell me that upfront. Unfortunately charlatans even with MD after their name do still exist. read more

I went to see Dr. Fast because I was having chronic fatigue, the causes for which had not diagnosed by other doctors I had seen, including an allergist. Dr. Fast had some tests done and determined that I had certain food sensitivities (not allergies). This was a great surprise to me because these foods had been part of my diet for as long as I could remember. Dr. Fast said food allergies/sensitivities can occur at in any time in your life for the first time. Once I cleared my system and developed the right diet, my fatigue disappeared and has only occasionally returned, probably because I broke my diet. I also stopped taking certain heart medications which had fatigue side affects. I can not be more grateful to Dr. Fast. read more

Apparently you either love her or hate her....can't believe all of these one star reviews. I had an AWESOME experience with Dr. Fast, in fact I wish she was my PCP. The first twenty mins of my appointment, she sat down and asked a ton of questions about my background and health as well as my current environment. I appreciated that she took inventory of all of these possible factors that could impact my allergies/allergy like symptoms. She had a great sense of humor, talked a bit about her family which made her approachable, and then at the end of the appointment I left feeling relieved that I hadn't developed allergies. Thanks Dr. Fast! read more

Holy cow, she's a good doctor. If she did primary care, I'd ask her to be my PCP. I may ask her anyway. Not only has she addressed my allergies, she caught a neurological condition that escaped a Board Certified neurologist and had plagued me for years. She referred me for treatment and it changed my life. She's doesn't do that "not my table" thing that specialists tend to do.If she see's something that looks like an allergy but isn't, she makes sure you are supported to pursue the other causes for the symptom. What a gem! read more

I couldn't be happier with my experience today with Dr. Fast, Allergist Extraordinaire! True to her name, I had no absolutely no wait this AM, and also got referred to a lab upstairs in the same building, where I also didn't have to wait. I went in for an initial consultation and am really pleased with the progress we've made so far. The experience felt very integrative, connecting the dots between things that seem unrelated to the untrained eye. She put me in touch with another doctor that was in-network that didn't appear on my insurance carrier's website. Overall, very pleased. I definitely recommend her! read more

Dr. Fast's glowing reviews are well-deserved. She was attentive, efficient, and engaging. She really evaluates your needs, and what you want to accomplish. I saw her for a food allergy, and she promptly showed me possibilities on testing, treatment, and overall plan. She prescribed me medications, and when insurance and the pharmacy was kicking back and clarifying, her office was right on it to make sure I got what I need. I strongly recommend her. read more

Dr Fast is awesome. I want to stop being her patient and start being her friend. Clinically thorough and great bedside manner - probing questions and patient enough to get good responses (we called my mom while we were gathering information in order to find out how I responded as a 3 year old to different medications and environments). No nonsense approach to treating problems. Don't mess around - head over there... and get better. read more

Dr. Fast lives up to her name. She's fast-talking, quick-thinking, and genuinely more awesome than any other physician, allergist, or dermatologist I've ever seen combined. I went to see her for a combination of problems - eczema and food allergies - and she immediately pinpointed a few causes that other doctors have never given me before. And even if her brain and mouth move at warp speed, she was extremely patient with me, answering any questions I had, and walking me carefully through her solutions to my issues. I left the appointment feeling like I'd actually made progress towards fixing my problems instead of feeling that I'd wasted my $40 copay on a doctor that didn't know and didn't care about how to fix me. Only caveat: since Dr. Fast is so awesome, you should absolutely make an appointment as far in advance as possible. Took me a month and a half to get a spot with her. read more

I came to Dr. Fast per a referral from my current doctor at One Medical Group. I was having some allergic reactions and wasn't sure what was going on so I decided to see an allergist. Dr. Fast was very welcoming, friendly, and easy to talk to. I appreciated on how she listened to me, my condition, and my concerns. I also appreciated on how extensive her notes were on my condition, my background/environment, and the symptoms I was experiencing. She recommended that I get a full battery of tests to see what I was allergic to as well as recommended a new inhaler for my asthma. Dr. Fast was also super quick to get back to me about the results of my tests and faxing over my records/recommendations to my PCP back at One Medical. I'd highly recommend Dr. Fast as she's has a great bedside manner, a great listener, and very thorough in what she does. I'm glad that she was able to help find out what was wrong with me (and address some long term allergy issues)! I'd highly recommend! read more

She's awesome. Dr. Fast actually cares to see ya get better. As a life long sufferer of eczema, I've seen 10+ allergists in my lifetime. Most of the time, I get the attitude of tough luck, and the same old advice. Dr. Fast breaks down whatsharming you, and why . And then gives you realistic steps you can take care to get better. Sounds simple? She sure makes it seem that way! If you want something who knows what they are doing, and actually cares that you make some progress, give her a ring. Call months ahead of time, cause like all good doctors, her schedule is packed. read more

The coolest doc around. Hands down. I knew my sinuses had issues and I deduced it was probably allergies (although, I had no idea--I had never suffered from allergies until I made the move to SF), so my PA at Bayspring Medical Group handed me a sheet of local allergists that the office recommended. I randomly chose the office with which Dr. Fast practices...and I am SO GLAD/lucky I did. The office's receptionist is wonderful. It was very easy to make an appointment and she was very so nice and pleasant both on the phone and in-person. On the day of my appointment, Dr. Fast opened the door to the waiting area and greeted me with an apology: "I'm so sorry you've been waiting!" And I replied, "Oh, it's okay. It's barely been 5 minutes." And she said, "The average wait time for patients at doctors' offices is 15 minutes. I'm trying to get that down to zero." "Are you Dr. Fast?" I asked (she hadn't introduced herself to me yet). She replied, "Oh yes, I am. Hi!" And we shook hands. After that initial encounter, I knew I was in good hands with a real, down-to-earth doctor :) (How often are you greeted by an MD who first apologizes and then doesn't immediately introduce themselves as Dr. XX? Never!) The appointment was efficient and thorough, and I left feeling very taken care of by Dr. Fast. She's extremely easy to talk to and she cares about getting to the root of your allergies as quickly as possible. When I left her office, I knew exactly what I was allergic to and had a plan of action in place. I have seen her for a follow-up appointment since then and she was just as wonderful as the first time. read more

What are you waiting for? Go make an appointment! Dr. Fast is not only hilarious and, very fast, she clearly thinks critically and carefully about her patients and their cases. She considers your whole health picture and really sympathizes with you. She called me hours after my appointment at night to mention something she had thought of after our appointment. She's great. read more

Dr. Fast approaches your health in a holistic way. She takes the time to listen and really cares about your well-being. She's fabulous.

Dr. Fast is knowledgeable, empathetic, and warm. She is a wonderful listener and takes the patient, their experiences, and their symptoms seriously. She is also quite a talented diagnostician - in my case, she was able to figure out a complicated situation during the course of my first visit, with a few tests to confirm it. I would recommend her to anyone, for issues with allergies, asthma, or immunology. read more

Dr. Katharine Fast and her office team are wonderful! I was looking for an alternative to Dr. Schuman Tam & office; it seems he is the only one pediatricians/referral nurses like to direct patients to. My child's original appointment was not for another two months, but due to a cancellation we got in much sooner! Dr. Fast was refreshing to talk to. We walked out with a plan for the next allergy season, and are happy to have found a great allergist who also sees children! read more

All I can say is thank you dear G-d for Dr. Fast!!!! She's the best of the best of the best. I love love love her and I'm the pickiest of the picky when it comes to health care practitioners. All I can tell you is that she's on top of it and will be in your corner for everything and anything. read more

Dr. Fast saw my daughter for allergies a few years ago and I am still so offended by the experience that I have finally decided to write a review. She was not interested in what I had to say and was overtly condescending and rude. As someone else noted in these posts, she appeared to make an assessment about my daughter (and me) and cavalierly sent us away. She made me feel as though I was a "hyper mom" who had no idea what I was talking about or what was going on with my daughter. 3 years later, my daughter continues to limp along with pretty bad sinus issues, allergies and sleep apnea. At last, we are getting to the bottom of this with another allergist. I understand that not all doctors can be right all the time but the condescension is inexcusable. read more

Love Doc Fast's attention, energy, and personality. I feel comfortable talking to her. I have seen a few allergists and immunologists, and none of them figured out that my lungs and stomach was not the problem but my throat and sinus. They kept saying it was acid reflux or asthma - did all types of tests and ruled out both and other diagnoses. Dr. Fast quickly figured out that my throat and sinus was the issue - THANK YOU!! The receptionist is responsive and really nice. I always do feel a little bad for her because she seems to support more than Dr. Fast - she seems swamped but never confused or scattered. Easy to make appts and ask other questions but don't expect chit-chat because she is very busy - the office should really hire another person. read more

Dr Fast is a very caring and competent doctor. I wouldn't hesitate to recommend her to anyone

I never write bad reviews, but I have to do so because, mirroring similar sentiments to what another mom posted, this was the worst experience I have ever had with a physician. I brought my child in for allergy testing, full of hope that I would have answers that would assuage my concerns about his issue. She was extremely condescending and RUDE! I am very thick skinned but felt close to tears in her office, feeling helpless and akin to a child being chastised for not understanding and interpreting what she was telling me (which wasn't much) - for asking questions because I just wanted to COMPREHEND what she was telling me and wanted to come away from the appointment like any other person would, knowing what it is she specifically tested for and what the results meant both for the immediate future and for the long term future. She just didn't communicate well or explain the process; beginning or end results in laypeople terminology. I tried to ask questions but as noted, from the start, she was quick to become annoyed by anything I asked. I truly didn't understand. And she was in and out quickly without sitting down to lay things out for me like any other doctor would. And since I really wanted to get information and ask the questions again so that I could understand what his results were. to appease her, for fear of being berated for asking anything, I demured, self deprecatingly by saying "I don't mean to be rude but I am just trying to understand. I am not knowledgeable about allergies, allergens or any of this, could you please explain...' And she replied curtly "YOU have ALREADY ASKED me this question FOUR TIMES!...but I will tell you AGAIN..." I couldn't believe this was a doctor I was seeking help from for my son and I literally asked her to explain what something to me and this is how I was being treated! It was as if anything I asked her was a personal affront to her and she was immediately on the defensive against I don't know what! Just crazy. Truly. Additionally, I felt judged by her from the minute dialogue began. To start, when asked whether my children were vaccinated for the flu, I replied "No." To which she gave me a disapproving look and asked me agitatedly "Why not? Don't you know that thousands of people DIE from the flu each year?" And this was in front of my child! Very inappropriate and unprofessional of her to speak to me like that in front of my young child. I would never utter this in front of him because I wouldn't want to frighten him unnecessarily. It was extremely uncalled for. I wasn't asking much of her, nor am I a high maintenance person. I am kind and considerate of people. I would expect and hope that a physician would first and foremost, extend the same kindness and consideration and treat his/her patients with the respect and courtesy they implicitly deserve as a human being! And she was not one of those. I don't think she should be working with people. Period. read more

Apparently a great doctor but scheduling is impossible. My girlfriend waited around 3 months for an appointment and has been waiting 4 months to get an allergy test. They don't seem to be in a hurry to get her the testing that she needs. I wish there was an alternative but it seems like all the allergy doctors in SF died. I would say go with Katherine Fast but be prepared to wait 6-12 months before you get to any assistance. read more

Dr. Fast is amazing! I was referred from my current doctor at One Medical Group, after having low Immunoglobulin levels. I had being extremely ill for over 4 years and misdiagnoses multiple times. Dr. Fast diagnosed me with CVID and immediately got me started with replacement Immunoglobulin treatments. She is one of the kindess, most caring doctors ever. I was having problems with insurance refusing to cover my treatments and Dr. Fast went to bat for me. She spend countless hours on the phone with insurance as well as writing appeal letters to try to help me get coverage. By far one of the smartest, kindest, and best doctors ever. read more

I have to say that I am beyond impressed with Dr Fast. She shows a genuine concern and caring. I have been to countless doctors and specialists this past year. Dr Fast actually listens. Not only does she listen, she COMMUNICATES with you and your plan of care. I felt at home with talking with her. I wasn't quite awake when I did talk to her. She helped me get everything out that I needed to. She is an amazing doctor and person. I feel like I can really get to the bottom of what's going on with me by seeing her. I highly recommend Dr Fast. read more

Dr. Fast is incredible as a diagnostician and as a doctor. I have nothing but the utmost respect for her and greatly appreciate her expertise. read more

I just called this office twice. First time was put on hold for 5 mins. I thought probably they forgot, and I called up again. Same thing. Was on hold for 4 mins before I disconnected. They seem to be understaffed, Why else would they would keep a new patient on hold for 9 mins. read more

Dr. Fast lives up to her name. She diagnosed me with a rare genetic immunodeficiency within a few visits and got me on treatment that I am still taking. She is extremely smart, intuitive and genuinely wants to improve your quality of life. I owe a lot to Dr. Fast. Thank you. read more

Love this office and have been seeing Dr. Fast for a few months now. She is the best. I also love her office. Things have improved significantly and now that i know how to reach them its no problem. read more

Could not recommend Dr. Fast more! She helped me manage my allergies, and did so without writing a prescrip and getting me out of the door. I've learned a lot from her. She was also willing to work with me on finding affordable options when I didn't have health insurance. Thanks, Katharine!! read more

Dr Fast is the best allergist. I have been seeing her for approximately eight years primarily for my asthma. She has offered knowledgeable and creative solutions to various asthma issues. She is warm, friendly, and very caring. I highly recommend her for adults or children. read more

Dr. Fast is attentive, caring, thorough, and an excellent listener. Highly recommended!

Dr. Fast in the like the Doctor you always wanted to have. Someone who was real, looked at you, really listened - and cares. I think she is the best. I wish she could also be my PCP. I really appreciate her and trust her. read more

Really knows her stuff! Thorough and attentive.

It is INCREDIBLY important for everyone, who is experiencing allergy-type symptoms, to know that Dr. Fast is truly amazing. I have multiple chronic conditions, and have seen MANY MANY doctors over my lifetime in major cities across the US - NY, LA, Chicago, SF (I am a 29-year-old female). Particularly, over the past 7 years, I have seen over 10-15 different doctors to treat my swelling/hives symptoms. Each doctor I have seen until Dr. Fast has mistreated me and/or misdiagnosed me - or has simply disregarded my symptoms and done nothing. I am so thankful for Dr. Fast. She listened to my story and was instantly able to determine my condition and is now starting me on an appropriate treatment regimen. She mentioned my story is a textbook case of XXXX. If this initial treatment plan doesn't work, I am fully confident that Dr. Fast will remain on top of my case and get me the treatment I need. read more

I saw her to do basic allergy tests and they did some limited skin tests. However most of the time she was talking to me and I feel like she formed an opinion that I don't have allergies based on my personality and not scientifically. Basically if I can't demonstrate it quickly in her office it doesn't exist. And she recommended repeatedly that I move to Nevada desert which makes no sense to me if I have no allergies. read more

I was referred to Dr. Fast by my ENT MD Dr. Kim for a second opinion for some funky stuff that I had going on with my sinus'. Dr. Fast is an awesome ENT/Allergist. Here's my breakdown of my experience with her: Pros: 1) Friendly and efficient office staff. They are very professional. They even kept me on a waiting list and called within 3 days of scheduling my original appt. So I was able to get in much faster than originally planned. 2) Dr. Fast triaged me herself - which was interesting and enjoyable. You don't have to worry about repeating yourself twice to a medical assistant. 3) Dr. Fast is very thorough and asks a lot of questions about family and medical history - so please know your information or be prepared to bring it with you. She asks about everything. Which I love that because most doctors short-change you and don't really give a damn. But I was well prepared and know my medical history so things went very smoothly. 4) Allergy testing was a breeze. Dr. Fast took the time to explain what was going on what each result meant. She even provided me with a copy to take my results home. 5) I had more in-depth blood work done and called Dr. Fast's office to get the results because I was going back to my referring physician for a follow-up and I wanted to make sure that she was informed. Dr. Fast called me back herself and also followed up with the referring doctor that same day (and I even think it was within the hour). 6) office is very clean & temperature is well regulated. 7) no long waits or busy/crowded waiting area 8) Perhaps the most important thing: Dr. Fast has the best and most personable bed-side manner. She shakes your hand and talks about things that are real. Explains everything in layman's terms so you get it. Very friendly. Cons: 1) there aren't more doctors like Dr. Fast and unfortunately she can't be my doctor for everything else. Bottom line: I highly recommend her. They just don't make quality doctors like her anymore. You won't be sorry! read more